Don't use KH with buffering substrate. You will cause pH swings as the soil absorbs the KH, lowering the pH. You do a water change, add in more KH, you cause the pH to rise, then the soil absorbs the KH and the pH lowers. This also causes your soil to exhaust faster.
So.... put the Salty Shrimp GH/KH+ remineralizer aside, or return it. It will not be good for your situation unless you choose to set up a tank with sand, and from the sounds of it, you might be okay using straight tap water in that tank unless you wanted to go the remineralized RO water in that tank.
As far as algae, I'm not sure if you are having algae issues in one due to the proximity of a window??? I remember you mentioning having to block a window, but not sure if you managed to block out all the light or not.
Regardless, when you go to clean it up, don't clean *all* of it, leave some for the shrimp!
Bloody Mary and Cherries are not the same. Cherry, Fire Red, Sakura and Painted Fire Red are all the same color of shrimp, just different grades of coloration. Bloody Mary are a different color.
Cherry, Sakura, Fire Red, Painted Fire Red is like the grades in Crystal Shrimp... C, B, A, S, S+, SS and SSS. The difference is the amount of coloration.
Bloody Mary is to Cherry as Crystal Red is to Crystal Black. Same shrimp, different colors.
The difference between BM and Cherry Grades is that Cherries have an opaque shell (although lower grades are clear in some areas) where-as BM are translucent. You can see it best when you have one of each type of shrimp in a container and a bright light behind them. High grade BM can also have red flesh (aka red legs and pleopods) where-as all grades of cherries will have clear flesh (legs might be red, but pleopods and flesh are clear).
I haven't kept either colors/types yet, but I do want some BM Shrimp!
I do recommend trying to find someone who keeps their BM in Caridina parameters, so you'll have the best luck acclimating them to your tank without issues.